In recent years, human beings have focused their exploration on space, because we always dream of one day being able to leave the earth and go to other planets to explore and survive. However, in addition to space, there are still many unsolved mysteries on the earth itself, such as what is hidden inside the earth or in the depths of the vast ocean.
Nature's miraculous workmanship - the Mariana Trench
The deepest part of the ocean discovered by humans so far is the Mariana Trench. In recent years, various countries have also sent many deep-sea detectors to "explore", hoping to find some unknown things. Things that people know.
Unexpectedly, something that scientists least want to see appeared at 10,928 meters in the Mariana Trench, which is plastic . So, what exactly is in the Mariana Trench? Why did plastic travel such a long distance to get here? Is there still a pure land on earth that is not polluted by plastic? Next, let us take a look!
Plastic garbage at the bottom of the Mariana Trench
Exploration of the Mariana Trench
The Mariana Trench is the deepest ocean known to mankind. It is an arc-shaped trench. The depth of each location has a certain The total length is about 2550 kilometers.
The reason why I want to introduce this point in particular is because I hope everyone understands that not the entire Mariana Trench is at the same depth, and the depth of 10,928 meters can only be regarded as its current extreme value , because in the trench There may be deeper places.
The Mariana Trench is one of the most hostile areas.
But no matter what, everyone is really full of curiosity about this place where Mount Everest will not be exposed at the top, so we are constantly exploring the device. Under perfect conditions, investigations have been conducted at various depths in the Mariana Trench. Of course, driven by the idea of "pursuing the limit", the most visited area is the deepest part of the Mariana Trench.
So, what did scientists find here? Is there the kind of spectacle described by Verne in "Twenty Thousand Leagues Under the Sea"?
Concept map of "Twenty Thousand Leagues Under the Sea"
According to the relevant photos disclosed and the descriptions of researchers, the Mariana Trench has indeed subverted people's imagination. Because we always thought that there would be no life in this high-pressure, low-temperature, and material-poor environment, but in fact, there are still many creatures living in this abyss.
data shows that due to the effect of the earth's gravity, the hydrostatic pressure in the seawater increases by 1MPa for every 100 meters the depth of the seawater drops. The average pressure in the deep sea is 38MPa. In the Mariana Trench, which is about 11,000 meters in the deepest part of the world's oceans, The hydrostatic pressure can reach up to 110MPa.
The creatures in the Mariana Trench
Although their visual organs have long degraded due to being in the dark seabed for a long time, their survival conditions are still very good. Watching these creatures living freely on the seabed would have made scientists very happy, and they would also marvel at the strength of life. But then something appeared in the field of vision that scientists least wanted to see. It was plastic .
There are 8.5 million tons of garbage in the sea every year
Plastics have long been spread all over the ocean
Plastic products should be regarded as very common things in life. People do get convenience when using them, but because this kind of thing is difficult to be Degradation, so it also brings serious environmental problems .
In our opinion, the areas invaded by plastic may only be limited to the surface or middle layers of the ocean, but we did not expect that plastic has already reached the deepest part of the ocean.
It is urgent to solve the problem of plastic pollution
It turns out that in 2019, an American explorer personally went to the Challenger Deep in the Mariana Trench to explore, and the depth reached 10,928 meters, setting a new record. .
After returning to the sea, he was proud of his success, but he was also very worried. Because he actually saw many broken plastic bags and candy wrappers on the seabed at this depth.
10 The discovery of plastic bags in the 28-meter-deep sea
undoubtedly proves that plastic has successfully invaded regardless of the depth. And because they are difficult to degrade, these plastics will remain on the seabed for a long time, polluting the ecological environment here.
In addition, when British scientists previously inspected the six deepest trenches in the world, they found that nearly 80% of the creatures there had plastic residues in their digestive systems. Take the Mariana Trench, for example, where samples contained even higher amounts of plastic than ingested by offshore organisms.
The Gammarodactylus was named plastic because its body is full of plastic waste.
This discovery was published in the British journal "Royal Society Open Science", and the research results clearly indicate that there are no marine ecosystems on the earth that are not necessarily contaminated by plastics. .
It is worth mentioning that, in addition to this visible "big plastic", the more terrifying pollution may be microplastics. This kind of microplastic is formed after plastic is continuously cracked under various effects, and its size is often less than 5mm. It can be seen from the size that microplastics are actually difficult to observe. They are secondary microplastics formed by the cracking of large plastics.
Microplastics under the microscope
New pollutants - microplastics
The reason why scientists are particularly concerned about the pollution of microplastics is mainly because these "tiny plastics" will be eaten by organisms on the seabed, and eventually directly enter the ecological cycle . And we may be unaware of this intrusion.
data shows that Fischer found large pieces of plastic and microplastics in the trench slope sediments at 5,000 meters in the Kuril-Kamchatka Trench. The large plastics were mainly fishing nets and packaging, and the abundance of microplastics ranged from 60 to 2,000 pieces per square meter. meters, 75% of which are fibrous microplastics smaller than 1mm.
Schematic diagram of microplastics entering the ecological cycle
And as time goes by, the content of microplastics in the ocean is becoming higher and higher. Of course, you may be curious as to why the microplastic content in organisms living in ocean trenches is higher than that of organisms on the sea surface. This is mainly determined by the lack of environmental resources.
After all, there are very few nutrients that can be taken in at the bottom of the sea. So when you are "hungry", taking in more plastic can be regarded as filling your stomach. And compared with large plastics, the harm of microplastics will only appear over time.
Schematic diagram of how microplastics enter the ocean
However, due to the small size of microplastics, easy adsorption of persistent organic matter, and transfer along the food chain, many scientists believe that its ecological impact is still very serious .
If humans sit idly by and do nothing, these microplastics will sooner or later enter our bodies along with the ecological cycle, causing harm to our bodies. In this case, many scientists are calling for microplastics to be listed as persistent organic pollutants .
A small amount of microplastics will remain in the body, affecting health
Of course, scientists say that although humans do not want to see plastics appearing on the seabed, more and more evidence has proven that in the abyss where humans rarely set foot, it has long been Surrounded by plastic. And according to research, the content of microplastics in the abyssal trenches is already higher than the microplastics in the traditional deep sea.
"Invisible Killer" - Microplastics
Microplastics in the Abyssal Trench
As we mentioned in the previous article, there are still many organisms living in the Mariana Trench, so scientists not only took samples from the water body, also Many samples of were obtained from organisms.
What is shocking is that the pollution situation in abyssal trenches seems to become more serious as the depth increases. For example, when compared with other sea areas, the Mariana Trench has become the hardest hit area for microplastic pollution.
According to the results of Peng By comparison with eight other studies, the abundance of microplastics at 10903m was four times that of the waters near Vancouver and 20 times higher than the deep-sea sediments of the Atlantic Ocean.
Schematic diagram of microplastics in different areas of the Mariana Trench
The high concentration of microplastics in the abyssal trench tells us one thing, that microplastics have spread all over the ocean, and this has also become the main storage area of for microplastics . Therefore, if you still regard the Abyss Trench as the last piece of pure land in the ocean before this, you can change your mind after reading this.
In addition, scientists believe that the migration of microplastics from the surface to the abyssal trenches still undergoes a relatively complex process. In terms of biological and physical processes, high concentrations of microplastics such as indicate that pollution is faster and more serious than we imagined .
Schematic diagram of the abundance of microplastics in the eastern tropical Pacific
Today, microplastics have been ingested by many marine species, among them there are producers and consumers, and even whales have large amounts of microplastics in their bodies. This makes the whale's gift to the sea after death become a way for "plastic" to sink to the bottom of the sea.
Don’t let the ocean become a dumping ground for plastic waste!
Therefore, for the sake of the health of the ocean ecosystem, we must face up to the problem of plastic pollution. Don’t think that just because large pieces of plastic are invisible is a good thing. There is often a greater crisis hidden behind it. Especially in ocean trenches, it is difficult for the pollution entering here to be discharged and can only wait to be slowly dissipated.
